1. Field of the Invention
The invention relates to a deicing salt composition, and more particularly to an ecological deicing salt composition comprising formate as the main ingredient.
2. Description of the Related Art
Conventional chlorine deicers contain chlorine ions and thus are corrosive. Although rust inhibitors (slushing compounds) are always added into chlorine deicers to reduce the corrosiveness on metals and road construction materials, the corrosiveness is still prominent. Furthermore, chlorine ions have an impact on soils and vegetations, and do harm to the growth of plants. Biological deicers made from grain crops, waste water originated from paper-making, wine by-products, and lipolysaccharide products have low cost and no environmental pollution, however, the deicing effect is not so good. Urea deicers are apt to degrade into ammonia, and calcium nitrate and magnesium nitrate deicing salt contain nitrate radical, both of which may result in eutrophication. Alcohol deicing salts containing glycol or glycerin have a high COD (Chemical Oxygen Demand) value.
Formate salts are new organic deicing salts, with fast and effective deicing ability, easy degradation, low oxygen demand, and little impact on the environment. Thus, it is a mild deicing salt friendly to ecology and the environment. However, formate has certain corrosive effect on metals, particularly on light metals, and thus, rust inhibitors must be added to compromise the corrosiveness. In the prior art, inorganic phosphates are generally employed as rust inhibitors, which, however, will react with calcium ions in the water to form calcium carbonate. Thus, a scale inhibitor is needed. Furthermore, inorganic phosphates in the water stimulate the growth of algae and thus result in water eutrophication.